1. Field of the Invention
The present invention relates to crop pickup devices, and, more particularly, to a crop pickup method and device for a baler.
2. Description of the Related Art
Although balers can be self-propelled, a common configuration is for a baler to be towed behind a tractor, the baler being supplied power by way of the tractor power-take-off unit. Balers are often characterized as round balers or square balers. Square balers typically have a plunging mechanism that takes the crop that is picked up, cuts and compresses the crop material into a square bale that is then tied with two strands of twine. Round balers use a crop pickup device to direct the hay to belts that are moving, causing the hay to form in a substantially cylindrical bale. Once the round bale is formed, it is often wrapped in a mesh or film or even wrapped with a winding of twine.
The pickup mechanism of a baler typically has a rotating pickup reel having pickup teeth or tines that pickup the crop that is in a windrow. The rotating tines rotate about an axis where the tines beneath the axis are moving in the direction that the baler is being propelled so that the tines get under and lift up the crop material and deliver it to another section that further moves the harvested crop.
When obstacles are encountered by the tines of the pickup reel, it can result in damage to the tines and/or the drive mechanism. For example, a pickup reel with stiff teeth, such as those illustrated in U.S. Pat. No. 5,394,682 need to be moved so that they are not damaged when encountering an obstacle. One previous solution includes floating springs and another solution involves a hydraulic float that can be utilized to reduce damage, each allowing the pickup assembly to lift in reaction to the force of the teeth contacting the ground or an object, such as a rock. There is a negative consequence from using these types of solutions in that the pickup head typically will bounce up and down in response to an obstacle, causing crop material to be missed in the field. This negative consequence is amplified as baling speeds increase.
What is needed in the art is a method and an apparatus to quickly respond to an obstacle yet eliminate the negative bounce consequence of previous solutions.